Abstract: Systems, methods and apparatuses provide for technology that includes a motor, a trigger assembly including a trigger member and an elastomer member mechanically coupled to the trigger member and moveable along a movement axis, wherein the elastomer member includes an electrically-conductive non-planar surface, a controller configured to operate the motor, and a circuit board oriented substantially perpendicularly to the movement axis, the circuit board including a plurality of conductive tracks facing the non-planar surface coupled to a resistor divider, and wherein controller is configured to vary a speed of the motor based on a number of the plurality of conductive tracks contacted by the non-planar surface of the elastomer member. The elastomer member may include a non-planar surface having a conductive central region, a conductive peripheral region and an insulative region positioned between the conductive central region and the conductive peripheral region.